Spark-plug



J. SHARP.

SPARK PLUG.

APPLICATION FILED AUG.23, 1919.

1,366,602. Patented Jan. 25, 1921.

warren JOHN SHARP, OI? GLEVELAND, OHIO.

SPABJK-PLUG'.

LSGQLEGQ.

Specification of Letters Patent.

Patented Jan. 25, 1921.

Application filed August 23, 1919. Serial No. 319,115.

To all whom it may concern:

Be it known that 1, JOHN SHARP, a citi- Zen of the United States, and resident of 3317 W. 25 bit, Cleveland, in the county of Cuyahoga and State of @hio, have invented certain new and useful improvements in Sparl PlLigs, of which I hereby declare the "following to be a'iull, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

The objects of the invention are to provide a separate ring shaped wire terminal having its extremities extended at right angles to the ring sides, and bent radially inwardly and also upwardly in the direction of the central electrode.

It includes also a rigid securing means for the wire terminal comprising the annular side walls or a narrow deep annular groove formed in the extremity of the spark plug, the said side walls being wrapped about the sides of said ring-shaped part of said terminal, thus inclosing it in an annular tube, in which it is rigidly held, and by means of which a good electrical and mechanical contact is provided.

This groove is readily formed when machining the body, and by its use, time and labor are economized and a more eliicient and durable device is produced. v

The invention is disclosed in the accompanying drawings hereinafter more fully described and specifically pointed out in the claims.

In the accompanying drawings, Figure 1 is a longitudinal section of a spark plug,

showing the invention applied to the extremity of the body of the plug; Fig. 2 is an enlarged similar section showing the same; Fig. 3 is a bottom view of Fig. 2; Figs. 4, 5, 6, 7 show modifications oi the body terminal; Fig. 8 is a plan of the cap for the central insulation; Fig. 9 is a section of the channeled body showing the invention applied to both terminals in a modified form.

In these views A is the metal body of the spark plugs. The inner extremity of which is deeply channeled at B. In the circular channel thus inade a split ring or arcuate wire C is inserted, one extremity of which C is turned outwardly and then radially inward at C It is also preferably bent upward to form an elbow C from which the oil can drip so that it will not hang upon the sparking end of the terminal.

applicant forms a deep annular narrow groove in the inner extremity of the plug body, the thin walls of which are integral and parallel with the longitudinal axis of the plug. Between the deep side walls of this groove, the wire, ring shaped part, of the terminal is rigidly inclosed.

It is positioned at the bottom of the annular groove and the walls of the groove ez-ztend beyond the ring body, and the inner wall is pressed outwardly over the inner side of the wire, and the outer wall is pressed inwardly over the outer side of the wire, forming a split annular tube, and making a permanent contact that heat will not affect and which cannot loosen, also no obstruction is formedto the free circulation or gas around the extended points C and central electrode D, also the opening left in the extremity of the plug is large and free to allow for cleaning without disassembling the plug.

The channel B is easily cut in the end of the body when machining the same and the edges of the channel are easily pressed around the wire to secure it in place.

in Fig. l, two wire arcs are shown and two opposite projecting terminals. In Fig. 5, a split ring is provided with two terminals in parallel relation to each other.

In Big. 6, two halves of a ring are each provided with a terminal and the terminals are arranged on the same side of the ring in parallel relation to each other. In Fig. 7, a split ring is provided with one terminal. in Fig. 9 one flange of the channel is made wider than the other.

Either flange may be made wider than the other as shown in Fig. 9 or both may be oi the same width as shown in Fig. 2. In

vFig. 8, a split cap is shown for the central lnsulation. This cap 1s made of spring metal and the split serves to make the cap resilient so that when the clamping nuts, L. L. are screwed down thereon, they will be held from movement and the nuts will not be loosened by the vibrations of the engine.

In F 9 both body and central terminals are provided with channels to receive wire terminals at the outer end at N. The channels are made so deep that the walls can be turned over the wire rings to prevent possible escape or movement of the rings.

The joint is always tight in the plug, since the walls are closed by pressure about the wire ring, and no amount of expansion or contraction will loosen them; also the heat is quickly conveyed away from the wire tip, since it is embedded in the metal. Also this construction leaves a smooth rounded end upon the extremity of the plug and the narrow slit running between the folded edges of the walls, forms an annular split in the tube in which the ring is embedded. This split will retain any oil which is likely collect on the extremity or" the plug and will burn off without running to spark gap.

Having described the invention, what I claim as new and desire to secure by Letters Patent is:

l. A spark plug comprising, a body having a deeprannular groove in its inner extremity, an annular wire terminal located in the bottom of said groove, the outer edges of the walls of said groove inclosing said wire on all sides, forming an annular split tube,

in which said wire terminal is embedded, the split 1n said tube providlng a retalnmg means for oil' flowing from the body of said spark plug.

2. In a spark plug; a body provided with a deep annular groove in its inner end, an

annular ring shaped terminal therein, said groove forming a split annular tube between the sides of which said ring is embedded, said sides forming a rounded annular' extremity for said boc y.

3. In a spark plug, a body provided with an annular split tube integral with its lower end, and an annular wire terminal embedded within said split tube.

4. In a sparl: plug. a body provided with an annular split tube integral with its lower end and an annular wire terminal embedded within said tube, a central metal terminal insulated from said body.

5. In a spark plug a body having deep annular groove in its inner extremity, a wire terminal having a ring shaped portion inclosed between the sides of said groove, said wire terminal having parallel sparking points extending integrally from said ring shaped portion.

In testimony whereof, I hereunto hand this 20 day of August, 1919.

JOHN SHARP set my In presence of- S. W. SANosran, WM. M. MONROE. 

